Stochastic Physics Namelist¶
General options¶
| Option | Description |
|---|---|
| NTRUNC | Optional, Spectral resolution (e.g. T126) of random patterns, default is for model to determine proper truncation |
| LAT_S | Optional, number of latitude points for the gaussian grid (must be even), default is for model to determine gaussian grid |
| LON_S | Optional, number of longitude points for the gaussian grid (recommend 2xLAT_S, default is for model to determine gaussian grid |
| FHSTOCH | Optional, forecast hour to write out random pattern in order to restart the pattern for a different forecast (used in DA), file is stoch_out.F<HHH> |
| STOCHINI | Optional, set to true if wanting to read in a previous random pattern (input file needs to be named stoch_ini). |
SPPT options¶
| Option | Description |
|---|---|
| DO_SPPT | logical to tell parent atmospheric model to use SPPT |
| SPPT | Amplitudes of random patterns (0.8,0.4,0.2,0.08,0.04) * |
| SPPT_TAU | Decorrelation timescales in seconds (21600,1.728E5,6.912E5,7.776E6,3.1536E7) * |
| SPPT_LSCALE | Decorrelation spatial scales in meters (250.E3,1000.E3,2000.E3,2000.E3,2000.E3) * |
| SPPT_LOGIT | Should be true to limit the SPPT perturbations between 0 and 2. Otherwise model will crash. |
| ISEED_SPPT | Seeds for setting the random number sequence (ignored if stochini is true) |
| SPPT_SIGTOP1 | lower sigma level to taper perturbations to zero (default is 0.1) |
| SPPT_SIGTOP2 | upper sigma level to taper perturbations to zero (0.025) |
| SPPT_SFCLIMIT | .T.=tapers the SPPT perturbations to zero at model’s lowest level (helps reduce model crashes) |
| SPPTINT | Optional, interval in seconds to update random pattern. Perturbations still get applied every time-step |
| USE_ZMTNBLCK | .T.=do not apply perturbations below the dividing streamline that is diagnosed by the gravity wave drag, mountain blocking scheme |
* SPPT uses 5 different patterns of varying time/length scales that are added together before being passed to physics
SHUM options¶
| Option | Description |
|---|---|
| DO_SHUM | logical to tell parent atmospheric model to use SHUM |
| SHUM | Amplitudes of random patterns (0.004) |
| SHUM_TAU | Decorrelation timescales in seconds (21600) |
| SHUM_LSCALE | ecorrelation spatial scales in meters (250000) |
| SHUM_SIGEFOLD | e-folding lengthscale (in units of sigma) of specific humidity perturbations, default is 0.2) |
| SHUMINT | Optional, interval in seconds to update random pattern. Perturbations still get applied every time-step |
| ISEED_SHUM | Seeds for setting the random number sequence (ignored if stochini is true). |
SKEB options¶
| Option | Description |
|---|---|
| DO_SKEB | logical to tell parent atmospheric model to use SKEB |
| SKEB | Amplitudes of random patterns (0.5) |
| SKEB_TAU | Decorrelation timescales in seconds (21600) |
| SKEB_LSCALE | Decorrelation spatial scales in meters (250) |
| ISEED_SKEB | Seeds for setting the random number sequence (ignored if stochini is true). |
| SKEBNORM | 0-random pattern is stream function, 1-pattern is K.E. norm, 2-pattern is vorticity (default is 0) |
| SKEB_VARSPECT_OPT | 0-gaussian (default), 1-power law (not tested) |
| SKEB_NPASS | number of passes of the del2 smoothing for the dissipation estimate (default is 11, minimum is 3) |
| SKEB_VDOF | the number of degrees of freedom in the vertical for the SKEB random pattern (default is 5) |
| SKEB_SIGTOP1 | lower sigma level to taper perturbations to zero (default is 0.1) |
| SKEB_SIGTOP2 | upper sigma level to taper perturbations to zero (0.025) |
| SKEBINT | Optional, interval in seconds to update random pattern. Perturbations still get applied every time-step |